BACKGROUND: Violence against pregnant women has been associated with gestational and perinatal disorders. Psychological violence is the type least investigated and its associated factors have been little studied. The present study was conducted in order to estimate prevalence rates and analyze the factors associated with exclusive and recurrent psychological violence in the municipality of São Luís, Brazil. METHODS: Data regarding 982 pregnant women, aged from 14 to 45 years, interviewed in 2010 and 2011 in a prenatal cohort were used. A self-applied questionnaire was used to screen for violence. Pregnant women submitted to physical and sexual violence were excluded from the analysis of factors associated with exclusive psychological violence. Prevalence ratios and 95% confidence intervals were estimated by a Poisson regression model with a hierarchical approach at three levels. At level 1 of the theoretical-conceptual model, we analyzed demographic and socioeconomic characteristics and variables that express gender inequalities; at level 2, we analyzed social support received by the women, and at level 3, the life experiences of the pregnant women. RESULTS: Prevalence rate of exclusive psychological violence was 41.6% and of recurrent violence was 32.6%. Exclusive psychological violence was associated with pregnant women's age of 14 to 18 years (PR: 1.32 95% CI: 1.04 - 1.70), pregnant women's schooling superior to that of her intimate partner (PR: 1.54 95% CI: 1.09 - 2.16), inadequate social affective support/positive social interaction (PR: 1.34 95% CI: 1.11 - 1.62), use of illicit drugs by the pregnant women (PR: 1.80 95% CI: 1.16 - 2.81) and having had six or more intimate partners in life (PR: 1.52 95% CI: 1.18 - 1.96). Recurrent exclusive psychological violence was associated with inadequate social affective support/positive social interaction (PR: 1.47 95% CI: 1.15 - 1.87), use of illicit drugs by the pregnant women (PR: 2,28 95% CI: 1,40 - 3,71) and having had six or more intimate partners in life (PR: 1.47 95% CI: 1.06 - 2.03). CONCLUSIONS: Psychological violence was a common phenomenon in this population of pregnant women that was associated with gender inequalities, inadequate social support and illicit drug use and should be routinely investigated during prenatal visits at health care services.